This invention relates to a finishing unit for a vehicle surface treatment apparatus and, more particularly, to an arrangement for stiffening the performance characteristic of a thin sheet-like pad of material secured to a rotating drum, the outer edges of which are adapted to engage the surface of the vehicle for facilitating a treatment thereof.
It is common place in vehicle surface treatment apparatus to mount pads of cloth or closed-cell foam to a rotating drum to cause the distal ends of the pads to engage the surface of the vehicle to effect the appropriate treatment of the surface. When the apparatus is a vehicle surface washing apparatus, liquid, such as water, is used in conjunction with the pads and various chemicals, such as soap and the like, are mixed so that the pads will effect the appropriate cleaning of the vehicle surface. In order to prevent damage to the vehicle surface during a surface treatment procedure, it is desirable to use lighter weight material for the pads. This has been accomplished by making the pads of thin sheet-like cloth and closed-cell foam. However, as the vehicle approaches a rotating mechanism on which is mounted a plurality of such pads, the rotating drum will continue to move toward the vehicle surface as the vehicle approaches to in effect cause the surface area of the material of the pads to be dragged across the vehicle surface. It has been noted in the past that the cleaning performance characteristic of the pads is enhanced when only the distal end portion of the pads engages the vehicle surface. When cloth material is used for the pad, the liquid will be absorbed into it thereby giving it more body causing the pad to remain somewhat stiff as it is being rotated with the drum to facilitate engagement of the distal ends thereof with the vehicle surface. However, even when the material is cloth, it is generally thin and lacks the desired stiffness characteristic to prevent a major surface area of the pad from being dragged across the vehicle surface thereby lessening the cleaning ability or lessening the chance of damage to the drum as well as to the vehicle surface. Further, maintaining engagement of only the distal end portions of the pad material will enhance the lifetime of the pad.
The issue of a major surface area of the pad material being dragged across the vehicle surface becomes even more critical when a lighter weight material, such as a closed-cell foam material, is used. Foam, compared to a cloth material, has very little body or bulk and it does not absorb liquid. Thus, it lacks the requisite ability to maintain only the distal ends thereof in engagement with the vehicle surface.
Therefore, it is a desire of this invention to provide finishing units as well as a vehicle surface treatment apparatus using such finishing units wherein a stiffness characteristic is introduced into the pad material to facilitate a maintaining of the distal end portion of the pad in engagement with the vehicle surface.
The objects and purposes of the invention are met by providing a finishing unit for a vehicle surface treatment apparatus composed of a thin sheet-like pad of material having flexible characteristics, the pad being adapted for contact with a vehicle surface. A buffer member of flexible material is a thin sheet-like member having a width comparable to the width of the pad and a length substantially shorter than the length of the pad. The buffer member overlays an opposing surface of the pad. A stiffening structure is oriented over a majority of the opposing surface areas of the buffer member and the pad and effects a fixed securement of the opposing surface areas of the buffer member and the pad together so as to provide an area of substantially less flexibility than the individual flexibility characteristic of each of the buffer member and the pad.